As someone who grew up in the 1950s carrying a knife was a way of life. No not for stabbing people... for cutting things.
Back then boys more or less all had a penknife, indeed many carried a sheth knife out in the woods, as did all boy scouts in those days, it wasn't seen as threatening, just the norm. So thats what I was used to.
Fast forward to today and finding a knife that UK legal to carry is harder than you might think, the law is simple enough... well sort of. Any knife with a folding non locking blade under three inches is legal to carry anywhere (with a few exceptions like courts) without you needing a reason to carry it. Any other knife, locking blade or fixed blade is legal to carry in a public place provided you have a good reason to carry it.
So a chef carrying a set of ten inch razor sharp knives is fine on his way to work, carry them to a football match and your in trouble, and rightly so. The problem is a locking three inch blade is a lot safer and no more dangerous than a folding three inch blade, so the logic is a bit flawed. But thats the law. Now we get to the swiss army part.
As I said finding a non locking knife isn't easy, nearly all hiking and camping, and ALL fishing shops sell a huge varity of folding knives, nearly all locking, the fact you cant legally just carry them around seems to have escaped their attention. Victorinox (swiss army to you and me) make a large selection of UK legal knives.
Many years ago I had a swiss army knife, and bloody good it was too. I lost it swiming one day (long story) and switched to multitools folding pliers type things with a varity before finding a Gerber, fantastic quality and bloody expensive... sadly it has locking blades so strictly speaking you cant carry it without a good reason. Recenty I rediscovered swiss army, and now I'm hooked.
Not only are they well made, they are fairly priced and better still theres a massive selection to choose from, plus if you cant find an off the shelf one to suit your needs (unlikely) they will make you a custom one with your choice of tools, they also have easily the best woodsaw of any multitool. Plus most are legal to carry, they do make a few with locking blades so check if you decide to buy one.
Now all I have to do is not loose the one I have, this was a fair bit more expensive than the one I lost but it is in a belt pouch not a pocket like the last one, and to be fair I don't swim with my trousers on if I can help it..... Not with the weight I carry anyway....